Heretofore, when it was necessary to join a plastic tube to a web of plastic in a high speed operation, the web was placed around the exterior surface of the tube and then welded thereto. For example, see U.S. Pat. Nos. 3,322,590 and 3,558,397.
In U.S. Pat. No. 3,322,590, a plastic bag having a nipple is welded to a plastic tube by: inserting the end of the tube over a tapered electrode; inserting the nipple of the bag over the tube and electrode; inserting the nipple, tube, and electrode into a second electrode; and then passing an electronic current between the electrodes, thereby welding the nipple of the bag and the tube together. This method produces a bag having a nipple which is welded to the exterior surface of a tube.
U.S. Pat No. 3,558,397 teaches that a plastic bag having a nipple can be joined to the external surface of a tube by an electrode probe and jaw assembly electrodes. The jaw assembly electrodes comprise a plurality of blades which are set at right angles to the axis of the electrode. The resulting weld forms a plurality of ribs.